In recent years, several publications have described the huge impact that the subclinical form of Gumboro disease has had, especially due to the circulation of novel variant strains belonging to genogroup 2 (G2), that might not be controlled with current commercial Del-E Variant type vaccines.

A broad analysis of the characterization and circulation of G2 type viruses in different countries is necessary for a better understanding of the evolution of the virus and the implementation of proper measures to improve the control of the disease worldwide. A total of 106 G2 IBDV nucleotide sequences containing the hypervariable region of the capsid protein VP2 were analysed with the objective of evaluating their phylogenetic relatedness.